Derivatives and Hedge Accounting - Notional Amounts and Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Gross Derivative Assets
Notional Amount	$ 4,200	$ 4,896
Fair Value	505	624
Counterparty netting	(225)	(270)
Cash Collateral	(226)	(304)
Derivative assets(c)	54	50
Gross Derivative Liabilities
Notional Amount	4,018	3,702
Fair Value	546	622
Counterparty netting	(225)	(270)
Cash Collateral	(240)	(201)
Total derivative liabilities on consolidated balance sheet	81	151
Bifurcated embedded derivatives assets, fair value	3,200	3,200
Bifurcated embedded derivative liabilities, fair value	0	0
Derivatives designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	788	879
Fair Value	46	66
Gross Derivative Liabilities
Notional Amount	855	906
Fair Value	71	109
Derivatives not designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	874	841
Fair Value	250	277
Gross Derivative Liabilities
Notional Amount	948	913
Fair Value	278	304
Derivatives not designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	2,465	3,095
Fair Value	163	230
Gross Derivative Liabilities
Notional Amount	2,047	1,707
Fair Value	151	158
Derivatives not designated as hedging instruments | Equity contracts
Gross Derivative Assets
Notional Amount	21	29
Fair Value	15	20
Gross Derivative Liabilities
Notional Amount	21	29
Fair Value	15	20
Derivatives not designated as hedging instruments | Credit contracts
Gross Derivative Assets
Notional Amount	52	52
Fair Value	31	31
Gross Derivative Liabilities
Notional Amount	147	147
Fair Value	31	31
Derivatives not designated as hedging instruments | Credit contracts | CDS
Gross Derivative Liabilities
Notional Amount	46	48
Fair Value	30	30
Derivatives not designated as hedging instruments | Other contracts
Gross Derivative Assets
Notional Amount	0	0
Fair Value	0	0
Gross Derivative Liabilities
Notional Amount	0	0
Fair Value	$ 0	$ 0